Solar winds more powerful than first thought, fresh research suggests

Research fresh out of Technische Universität Wien in Austria suggests that solar winds are far more powerful than first thought, and can do much more damage than just projecting light into the Earth’s night sky.

Published in the planetology journal Icarus, the findings state that previous models of solar wind bombardment are incomplete, and its effects can be much more drastic than previously thought.

Solar wind bombardment refers to how the planets and moons of our solar system are continuously being bombarded by particles hurled away from the sun.

On Earth this has hardly any effect, apart from the northern lights, because the dense atmosphere and the magnetic field of the Earth protect us from these solar wind particles.

But on the Moon or on Mercury things are different: There, the uppermost layer of rock is gradually eroded by the impact of sun particles.

The new findings suggest studies into these winds were not as extensive as they could be, with TU Wien university finding that they are in actual fact much more damaging. These findings are important for the ESA mission BepiColombo, Europe’s first Mercury mission, as the study’s first author, Paul Szabo, explained:

“Up to now it was assumed that the kinetic energy of the fast particles is primarily responsible for atomization of the rock surface,” explained, PhD student in Friedrich Aumayr’s team and first author of the current publication.

“But this is only half the truth: we were able to show that the high electrical charge of the particles plays a decisive role. It is the reason that the particles on the surface can do much more damage than previously thought.

“When the particles of the solar wind are multiply charged, for example, when they lack several electrons, they carry a large amount of energy which is released in a flash on impact. If this is not taken into account, the effects of the solar wind on various rocks are misjudged,” added Szabo.

“Therefore, it is not possible to draw exact conclusions about the surface rocks with an incorrect model from the composition of the exosphere.”

Protons make up by far the largest part of the solar wind, and so it was previously thought that they had the strongest influence on the rock. But as it turns out, helium actually plays the main role because, unlike protons, it can be charged twice as positively. And the contribution of heavier ions with an even greater electrical charge must not be neglected either.

The Physics Institute of the University of Bern and the Space Institute of the Austrian Academy of Sciences in Graz will now also help contribute to the new findings to the analysis of the forthcoming ESA space mission.